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sites were discarded and other, nearby sites were sampled, although in some cases the three- <br />meter sampling radius was exceeded. <br />Counting and identification procedures: <br />All organisms in each sample were counted and identified to the smallest discernable taxon, <br />usually genus. The counts were made by emptying the sample into a five -inch circular petri <br />dish, from which each organism was removed and tallied. Magnification was used as <br />necessary for identification. Pennak (1978), Merritt and Cummins (1984), an d Ward an d <br />Kondratieff (1992) were used to identify specimens. Identification assistance and verification <br />was provided by Howard Rhodes of the Colorado State University Department of Entomology. <br />Habitat Characterization <br />Attributes of the stream habitat both upstream and downstream of the discharge was assessed <br />by this study. This included characterization of the physical habitat and substrate, water <br />characteristics, and condition of stream banks and surrounding riparian communities. Physical <br />habitat characterization, mostly involving stream cross - sections and pebble counts, was <br />conducted during November 14 and 15, 1994. Field measurement of water quality and <br />collection of water quality samples for laboratory analysis was done in conjunction with each <br />invertebrate sampling trip, and description of riparian habitats was conducted on August 12. <br />Physical Habitat: <br />A cross - section of the river was surveyed using a clinometer and steel tape at each of the five <br />upstream and downstream sample sites for a total of ten cross - sections. To measure the active <br />channel, the end of the steel tape was attached to a section of steel rebar driven into the bank, <br />then the tape was stretched across the river and attached to a second stake on the opposite <br />bank. The clinometer was used to adjust the elevation of the stakes to the same horizonta l <br />level, and to measure the catenary in the tape for later correction s vertical distances <br />measured from the tape to the stream bed. The vertical distance from the steel tape to the <br />water level and stream bed was measured using a carpenter's tape every two meters. At each <br />location, a Price AA current meter was used to measure water velocity. For water velocity <br />measurements, the meter was positioned at the 60 percent depth level, measured from the <br />bottom (e.g., if the water was 1 meter deep, the current meter was placed at a depth of 60 cm <br />off the bottom). Three pebble counts were conducted at approximately equally spaced intervals <br />across the cross - section. Each pebble count included estimates of the percentage of each <br />substrate size category and percentage of imbeddedness. In addition, general observations of <br />stream substrate size and variability were made while assessing riparian habitats along both <br />banks. The steel tape and clinometer was also used to extend the cross - sections beyond the <br />active channel to include the rest of the immediate floodplain by measuring slope lengths and <br />angles. <br />,, 7 <br />